Phoenix averages by month
These are NOAA 1991-2020 normals for Phoenix Sky Harbor International Airport, the reference station for Maricopa County.[1] Highs and lows are in °F, rain in inches.
| Month | Average high (°F) | Average low (°F) | Rain (in) |
|---|---|---|---|
| January | 67.6 | 46.0 | 0.87 |
| February | 70.8 | 49.0 | 0.87 |
| March | 78.1 | 54.5 | 0.83 |
| April | 85.5 | 60.8 | 0.22 |
| May | 94.5 | 69.5 | 0.13 |
| June | 104.2 | 78.6 | 0.02 |
| July | 106.5 | 84.5 | 0.91 |
| August | 105.1 | 83.6 | 0.93 |
| September | 100.4 | 78.1 | 0.57 |
| October | 89.2 | 65.6 | 0.56 |
| November | 76.5 | 53.7 | 0.57 |
| December | 66.2 | 45.3 | 0.74 |
The twelve rain normals add up to 7.22 inches a year. That total is our sum of the monthly rows.[1]
Which months run hottest and wettest
July is the warmest month, with an average high of 106.5 F. December is the coolest, with an average high of 66.2 F.[1]
The answer to "which month is the hottest in Arizona" at this station is July.
Depth
Average high by warm month
Start of the scale
- 89.2 °FOctober
- 100.4 °FSeptember
- 104.2 °FJune
- 105.1 °FAugust
- 106.5 °FJuly
The stretch from the top of the scale down to the first level is shortened; the distances between levels are to scale.
Check the lows too. July's average low is 84.5 F and August's is 83.6 F, so the nights barely cool off. Highs stay at or above 100 F from June through September, and October still averages 89.2 F.[1]
That is why the hot season can feel longer than it looks on a calendar. It's also why cooling equipment matters (HVAC in Arizona).
August is the wettest month at 0.93 inches, with July close behind at 0.91. June is the driest at 0.02.[1]
For what drives the summer rain, see monsoon season dates and home prep.
How Flagstaff, Tucson and Yuma compare
Each column shows the reference station for its county: Tucson International Airport for Pima, Flagstaff Pulliam Airport for Coconino, Yuma MCAS for Yuma.[2][3][4] Values are average high / average low in °F.
| Month | Phoenix | Tucson | Flagstaff | Yuma |
|---|---|---|---|---|
| January | 67.6 / 46.0 | 66.5 / 40.8 | 43.4 / 17.6 | 69.8 / 47.9 |
| April | 85.5 / 60.8 | 82.9 / 53.3 | 59.2 / 28.2 | 86.4 / 59.8 |
| July | 106.5 / 84.5 | 100.2 / 76.3 | 82.0 / 51.4 | 106.7 / 82.6 |
| October | 89.2 / 65.6 | 86.3 / 59.0 | 63.6 / 31.5 | 90.2 / 65.7 |
| Rain per year (in, our sum) | 7.22 | 10.61 | 20.52 | 3.28 |
Each figure represents one named station, not Maricopa, Pima, Coconino or Yuma County as a whole.
Flagstaff has the coldest winters, with a December average high of 43.0 F, and the most rain.[3] Yuma has the least rain, and its July average high of 106.7 F edges past Phoenix.[4]
Tucson's warmest month is June (101.2 F), and its wettest is July at 2.21 inches.[2]
For heat and monsoon rain by county, see the Arizona county heat table.
What a climate normal is and is not
A climate normal is a 30-year average. Phoenix's January normal, for example, is calculated from the 30 January averages observed from 1991 through 2020.[5]
It belongs to a station, not a whole county. The listed annual rainfall is 7.22 inches for Phoenix and 3.28 inches for Yuma, two stations with very different totals.[6]
A normal is also not a forecast. National Weather Service climate reports separate normal values from the temperatures and rain actually observed.[8]
That explains why figures elsewhere can differ. A mean temperature, an average high and a record high are different measures, and a July average high near 106 F is not a July mean.[7]
Check which station, which years and which measure any number uses.
Quick answers
Which month is hottest in Phoenix?
July, with an average high of 106.5 F.
Which month is coolest in Phoenix?
December, with an average high of 66.2 F.
How much rain does Phoenix get a year?
The monthly normals add up to 7.22 inches.
Sources
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Phoenix Sky Harbor International Airport (monthly)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00023183&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-TMIN-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Tucson International Airport (monthly)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00023160&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-TMIN-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Flagstaff Pulliam Airport (monthly)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003103&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-TMIN-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- NOAA National Centers for Environmental Information. "NOAA 1991-2020 Climate Normals, Yuma Mcas (monthly)." https://www.ncei.noaa.gov/access/services/data/v1?includeStationName=1&format=csv&stations=USW00003145&dataset=normals-monthly-1991-2020&dataTypes=MLY-TMAX-NORMAL,MLY-TMIN-NORMAL,MLY-PRCP-NORMAL. Accessed October 21, 2026.
- National Weather Service Phoenix. "1991-2020 Normals - Phoenix." https://www.weather.gov/psr/19912020Normals. Accessed October 21, 2026.
- National Weather Service Phoenix. "1991-2020 Normals - Phoenix." https://www.weather.gov/psr/19912020Normals. Accessed October 21, 2026.
- National Weather Service Phoenix. "Climatological Report (Monthly)." https://forecast.weather.gov/product.php?site=SJT&issuedby=PHX&product=CLM&format=CI&version=7&glossary=0. Accessed October 21, 2026.
- National Weather Service. "Climatological Report (Daily)." https://forecast.weather.gov/product.php?site=NWS&issuedby=PHX&product=CLI&format=CI&version=39&highlight=off&glossary=0. Accessed October 21, 2026.